Create/bind TCP and UDP listening sockets in pairs.
[tinc] / src / net.c
index 35d9563..5632727 100644 (file)
--- a/src/net.c
+++ b/src/net.c
@@ -1,7 +1,7 @@
 /*
     net.c -- most of the network code
-    Copyright (C) 1998-2001 Ivo Timmermans <itimmermans@bigfoot.com>,
-                  2000,2001 Guus Sliepen <guus@sliepen.warande.net>
+    Copyright (C) 1998-2002 Ivo Timmermans <itimmermans@bigfoot.com>,
+                  2000-2002 Guus Sliepen <guus@sliepen.warande.net>
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -17,7 +17,7 @@
     along with this program; if not, write to the Free Software
     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 
-    $Id: net.c,v 1.35.4.140 2001/10/28 08:41:19 guus Exp $
+    $Id: net.c,v 1.35.4.159 2002/03/01 13:18:54 guus Exp $
 */
 
 #include "config.h"
@@ -33,7 +33,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <sys/signal.h>
+#include <signal.h>
 #include <sys/time.h>
 #include <sys/types.h>
 #include <syslog.h>
 #include <net/if.h>
 
 #include <openssl/rand.h>
-#include <openssl/evp.h>
-#include <openssl/pem.h>
-
-#ifndef HAVE_RAND_PSEUDO_BYTES
-#define RAND_pseudo_bytes RAND_bytes
-#endif
 
 #include <utils.h>
 #include <xalloc.h>
 #include "process.h"
 #include "protocol.h"
 #include "subnet.h"
+#include "graph.h"
 #include "process.h"
 #include "route.h"
 #include "device.h"
+#include "event.h"
 
 #include "system.h"
 
-int maxtimeout = 900;
-int seconds_till_retry = 5;
-
-int tcp_socket = -1;
-int udp_socket = -1;
-
-int keylifetime = 0;
-int keyexpires = 0;
-
-/* VPN packet I/O */
-
-void receive_udppacket(node_t *n, vpn_packet_t *inpkt)
-{
-  vpn_packet_t outpkt;
-  int outlen, outpad;
-  EVP_CIPHER_CTX ctx;
-cp
-  /* Decrypt the packet */
-
-  EVP_DecryptInit(&ctx, myself->cipher, myself->key, myself->key + myself->cipher->key_len);
-  EVP_DecryptUpdate(&ctx, outpkt.salt, &outlen, inpkt->salt, inpkt->len);
-  EVP_DecryptFinal(&ctx, outpkt.salt + outlen, &outpad);
-  outlen += outpad;
-  outpkt.len = outlen - sizeof(outpkt.salt);
-
-  receive_packet(n, &outpkt);
-cp
-}
-
-void receive_tcppacket(connection_t *c, char *buffer, int len)
-{
-  vpn_packet_t outpkt;
-cp
-  outpkt.len = len;
-  memcpy(outpkt.data, buffer, len);
-
-  receive_packet(c->node, &outpkt);
-cp
-}
-
-void receive_packet(node_t *n, vpn_packet_t *packet)
-{
-cp
-  if(debug_lvl >= DEBUG_TRAFFIC)
-    syslog(LOG_DEBUG, _("Received packet of %d bytes from %s (%s)"), packet->len, n->name, n->hostname);
-
-  route_incoming(n, packet);
-cp
-}
-
-void send_udppacket(node_t *n, vpn_packet_t *inpkt)
-{
-  vpn_packet_t outpkt;
-  int outlen, outpad;
-  EVP_CIPHER_CTX ctx;
-  struct sockaddr_in to;
-  socklen_t tolen = sizeof(to);
-  vpn_packet_t *copy;
-cp
-  if(!n->status.validkey)
-    {
-      if(debug_lvl >= DEBUG_TRAFFIC)
-       syslog(LOG_INFO, _("No valid key known yet for %s (%s), queueing packet"),
-              n->name, n->hostname);
-
-      /* Since packet is on the stack of handle_tap_input(),
-         we have to make a copy of it first. */
-
-      copy = xmalloc(sizeof(vpn_packet_t));
-      memcpy(copy, inpkt, sizeof(vpn_packet_t));
-
-      list_insert_tail(n->queue, copy);
-
-      if(!n->status.waitingforkey)
-       send_req_key(n->nexthop->connection, myself, n);
-      return;
-    }
-
-  /* Encrypt the packet. */
-
-  RAND_pseudo_bytes(inpkt->salt, sizeof(inpkt->salt));
-
-  EVP_EncryptInit(&ctx, n->cipher, n->key, n->key + n->cipher->key_len);
-  EVP_EncryptUpdate(&ctx, outpkt.salt, &outlen, inpkt->salt, inpkt->len + sizeof(inpkt->salt));
-  EVP_EncryptFinal(&ctx, outpkt.salt + outlen, &outpad);
-  outlen += outpad;
-
-  to.sin_family = AF_INET;
-  to.sin_addr.s_addr = htonl(n->address);
-  to.sin_port = htons(n->port);
-
-  if((sendto(udp_socket, (char *) outpkt.salt, outlen, 0, (const struct sockaddr *)&to, tolen)) < 0)
-    {
-      syslog(LOG_ERR, _("Error sending packet to %s (%s): %m"),
-             n->name, n->hostname);
-      return;
-    }
-cp
-}
+int do_prune = 0;
+int do_purge = 0;
+int sighup = 0;
+int sigalrm = 0;
 
 /*
-  send a packet to the given vpn ip.
-*/
-void send_packet(node_t *n, vpn_packet_t *packet)
-{
-cp
-  if(debug_lvl >= DEBUG_TRAFFIC)
-    syslog(LOG_ERR, _("Sending packet of %d bytes to %s (%s)"),
-           packet->len, n->name, n->hostname);
-
-  if(n == myself)
-    {
-      if(debug_lvl >= DEBUG_TRAFFIC)
-        {
-          syslog(LOG_NOTICE, _("Packet is looping back to us!"));
-        }
-
-      return;
-    }
-
-  if(!n->status.active)
-    {
-      if(debug_lvl >= DEBUG_TRAFFIC)
-       syslog(LOG_INFO, _("%s (%s) is not active, dropping packet"),
-              n->name, n->hostname);
-
-      return;
-    }
-/* FIXME
-  if(n->via == myself)
-    via = n->nexthop;
-  else
-    via = n->via;
-
-  if(via != n && debug_lvl >= DEBUG_TRAFFIC)
-    syslog(LOG_ERR, _("Sending packet to %s via %s (%s)"),
-           n->name, via->name, via->hostname);
-
-  if((myself->options | via->options) & OPTION_TCPONLY)
-    {
-      if(send_tcppacket(via->connection, packet))
-        terminate_connection(via->connection, 1);
-    }
-  else
-    send_udppacket(via, packet);
+  put all file descriptors in an fd_set array
 */
-}
-
-/* Broadcast a packet to all active direct connections */
-
-void broadcast_packet(node_t *from, vpn_packet_t *packet)
+void build_fdset(fd_set *fs)
 {
   avl_node_t *node;
   connection_t *c;
+  int i;
 cp
-  if(debug_lvl >= DEBUG_TRAFFIC)
-    syslog(LOG_INFO, _("Broadcasting packet of %d bytes from %s (%s)"),
-          packet->len, from->name, from->hostname);
+  FD_ZERO(fs);
 
   for(node = connection_tree->head; node; node = node->next)
     {
       c = (connection_t *)node->data;
-      if(c->status.active && c != from->nexthop->connection)
-        send_packet(c->node, packet);
-    }
-cp
-}
-
-void flush_queue(node_t *n)
-{
-  list_node_t *node, *next;
-cp
-  if(debug_lvl >= DEBUG_TRAFFIC)
-    syslog(LOG_INFO, _("Flushing queue for %s (%s)"), n->name, n->hostname);
-
-  for(node = n->queue->head; node; node = next)
-    {
-      next = node->next;
-      send_udppacket(n, (vpn_packet_t *)node->data);
-      list_delete_node(n->queue, node);
-    }
-cp
-}
-
-/* Setup sockets */
-
-int setup_listen_socket(int port)
-{
-  int nfd, flags;
-  struct sockaddr_in a;
-  int option;
-  char *interface;
-  char *address;
-  ip_mask_t *ipmask;
-cp
-  if((nfd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
-    {
-      syslog(LOG_ERR, _("Creating metasocket failed: %m"));
-      return -1;
-    }
-
-  flags = fcntl(nfd, F_GETFL);
-  if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0)
-    {
-      close(nfd);
-      syslog(LOG_ERR, _("System call `%s' failed: %m"),
-            "fcntl");
-      return -1;
-    }
-
-  /* Optimize TCP settings */
-
-  option = 1;
-  setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
-  setsockopt(nfd, SOL_SOCKET, SO_KEEPALIVE, &option, sizeof(option));
-#ifdef HAVE_LINUX
-  setsockopt(nfd, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
-
-  option = IPTOS_LOWDELAY;
-  setsockopt(nfd, SOL_IP, IP_TOS, &option, sizeof(option));
-
-  if(get_config_string(lookup_config(config_tree, "BindToInterface"), &interface))
-    if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, interface, strlen(interface)))
-      {
-        close(nfd);
-        syslog(LOG_ERR, _("Can't bind to interface %s: %m"), interface);
-        return -1;
-      }
-#endif
-
-  memset(&a, 0, sizeof(a));
-  a.sin_family = AF_INET;
-  a.sin_addr.s_addr = htonl(INADDR_ANY);
-  a.sin_port = htons(port);
-
-  if(get_config_string(lookup_config(config_tree, "BindToAddress"), &address))
-    {
-      ipmask = strtoip(address);
-      if(ipmask)
-      {
-        a.sin_addr.s_addr = htonl(ipmask->address);
-        free(ipmask);
-      }
-    }
-
-  if(bind(nfd, (struct sockaddr *)&a, sizeof(struct sockaddr)))
-    {
-      close(nfd);
-      syslog(LOG_ERR, _("Can't bind to port %hd/tcp: %m"), port);
-      return -1;
-    }
-
-  if(listen(nfd, 3))
-    {
-      close(nfd);
-      syslog(LOG_ERR, _("System call `%s' failed: %m"),
-            "listen");
-      return -1;
-    }
-cp
-  return nfd;
-}
-
-int setup_vpn_in_socket(int port)
-{
-  int nfd, flags;
-  struct sockaddr_in a;
-  const int one = 1;
-cp
-  if((nfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0)
-    {
-      close(nfd);
-      syslog(LOG_ERR, _("Creating socket failed: %m"));
-      return -1;
+      FD_SET(c->socket, fs);
     }
 
-  setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
-
-  flags = fcntl(nfd, F_GETFL);
-  if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0)
+  for(i = 0; i < listen_sockets; i++)
     {
-      close(nfd);
-      syslog(LOG_ERR, _("System call `%s' failed: %m"),
-            "fcntl");
-      return -1;
+      FD_SET(tcp_socket[i], fs);
+      FD_SET(udp_socket[i], fs);
     }
 
-  memset(&a, 0, sizeof(a));
-  a.sin_family = AF_INET;
-  a.sin_port = htons(port);
-  a.sin_addr.s_addr = htonl(INADDR_ANY);
-
-  if(bind(nfd, (struct sockaddr *)&a, sizeof(struct sockaddr)))
-    {
-      close(nfd);
-      syslog(LOG_ERR, _("Can't bind to port %hd/udp: %m"), port);
-      return -1;
-    }
+  FD_SET(device_fd, fs);
 cp
-  return nfd;
 }
 
-int setup_outgoing_socket(connection_t *c)
-{
-  int flags;
-  struct sockaddr_in a;
-  int option;
-cp
-  if(debug_lvl >= DEBUG_CONNECTIONS)
-    syslog(LOG_INFO, _("Trying to connect to %s (%s)"), c->name, c->hostname);
-
-  c->socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
-
-  if(c->socket == -1)
-    {
-      syslog(LOG_ERR, _("Creating socket for %s port %d failed: %m"),
-             c->hostname, c->port);
-      return -1;
-    }
-
-  /* Bind first to get a fix on our source port???
-
-  a.sin_family = AF_INET;
-  a.sin_port = htons(0);
-  a.sin_addr.s_addr = htonl(INADDR_ANY);
-
-  if(bind(c->socket, (struct sockaddr *)&a, sizeof(struct sockaddr)))
-    {
-      close(c->socket);
-      syslog(LOG_ERR, _("System call `%s' failed: %m"), "bind");
-      return -1;
-    }
+/* Purge edges and subnets of unreachable nodes. Use carefully. */
 
-  */
-
-  /* Optimize TCP settings?
-
-  option = 1;
-  setsockopt(c->socket, SOL_SOCKET, SO_KEEPALIVE, &option, sizeof(option));
-#ifdef HAVE_LINUX
-  setsockopt(c->socket, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
-
-  option = IPTOS_LOWDELAY;
-  setsockopt(c->socket, SOL_IP, IP_TOS, &option, sizeof(option));
-#endif
-
-  */
-
-  /* Connect */
-
-  a.sin_family = AF_INET;
-  a.sin_port = htons(c->port);
-  a.sin_addr.s_addr = htonl(c->address);
-
-  if(connect(c->socket, (struct sockaddr *)&a, sizeof(a)) == -1)
-    {
-      close(c->socket);
-      syslog(LOG_ERR, _("%s port %hd: %m"), c->hostname, c->port);
-      return -1;
-    }
-
-  flags = fcntl(c->socket, F_GETFL);
-
-  if(fcntl(c->socket, F_SETFL, flags | O_NONBLOCK) < 0)
-    {
-      close(c->socket);
-      syslog(LOG_ERR, _("fcntl for %s port %d: %m"),
-             c->hostname, c->port);
-      return -1;
-    }
-
-  if(debug_lvl >= DEBUG_CONNECTIONS)
-    syslog(LOG_INFO, _("Connected to %s port %hd"),
-         c->hostname, c->port);
-cp
-  return 0;
-}
-
-int setup_outgoing_connection(char *name)
+void purge(void)
 {
+  avl_node_t *nnode, *nnext, *enode, *enext, *snode, *snext, *cnode;
+  node_t *n;
+  edge_t *e;
+  subnet_t *s;
   connection_t *c;
-  struct hostent *h;
-cp
-  c = new_connection();
-  c->name = xstrdup(name);
-
-  init_configuration(&c->config_tree);
-  read_connection_config(c);
-  
-  if(!get_config_string(lookup_config(c->config_tree, "Address"), &c->hostname))
-    {
-      syslog(LOG_ERR, _("No address specified for %s"), c->name);
-      free_connection(c);
-      return -1;
-    }
-
-  if(!get_config_port(lookup_config(c->config_tree, "Port"), &c->port))
-    {
-      syslog(LOG_ERR, _("No port specified for %s"), c->name);
-      free_connection(c);
-      return -1;
-    }
-
-  if(!(h = gethostbyname(c->hostname)))
-    {
-      syslog(LOG_ERR, _("Error looking up `%s': %m"), c->hostname);
-      free_connection(c);
-      return -1;
-    }
-
-  c->address = ntohl(*((ipv4_t*)(h->h_addr_list[0])));
-  c->hostname = hostlookup(htonl(c->address));
-
-  if(setup_outgoing_socket(c) < 0)
-    {
-      syslog(LOG_ERR, _("Could not set up a meta connection to %s (%s)"),
-             c->name, c->hostname);
-      free_connection(c);
-      return -1;
-    }
-
-  c->status.outgoing = 1;
-  c->last_ping_time = time(NULL);
-
-  connection_add(c);
-
-  send_id(c);
-cp
-  return 0;
-}
-
-int read_rsa_public_key(connection_t *c)
-{
-  FILE *fp;
-  char *fname;
-  char *key;
-  void *result;
 cp
-  if(!c->rsa_key)
-    c->rsa_key = RSA_new();
+  if(debug_lvl >= DEBUG_PROTOCOL)
+    syslog(LOG_DEBUG, _("Purging unreachable nodes"));
 
-  /* First, check for simple PublicKey statement */
+  for(nnode = node_tree->head; nnode; nnode = nnext)
+  {
+    nnext = nnode->next;
+    n = (node_t *)nnode->data;
 
-  if(get_config_string(lookup_config(c->config_tree, "PublicKey"), &key))
+    if(!n->status.reachable)
     {
-      BN_hex2bn(&c->rsa_key->n, key);
-      BN_hex2bn(&c->rsa_key->e, "FFFF");
-      return 0;
-    }
-
-  /* Else, check for PublicKeyFile statement and read it */
+      if(debug_lvl >= DEBUG_SCARY_THINGS)
+        syslog(LOG_DEBUG, _("Purging node %s (%s)"), n->name, n->hostname);
 
-  if(get_config_string(lookup_config(c->config_tree, "PublicKeyFile"), &fname))
-    {
-      if(is_safe_path(fname))
-        {
-          if((fp = fopen(fname, "r")) == NULL)
-            {
-              syslog(LOG_ERR, _("Error reading RSA public key file `%s': %m"),
-                    fname);
-              return -1;
-            }
-          result = PEM_read_RSAPublicKey(fp, &c->rsa_key, NULL, NULL);
-          fclose(fp);
-          if(!result)
-            {
-              syslog(LOG_ERR, _("Reading RSA public key file `%s' failed: %m"),
-                    fname);
-              return -1;
-            }
-          return 0;
-        }
-      else
-        return -1;
-    }
-
-  /* Else, check if a harnessed public key is in the config file */
-
-  result = NULL;
-
-  asprintf(&fname, "%s/hosts/%s", confbase, c->name);
-  if((fp = fopen(fname, "r")))
-    {
-      result = PEM_read_RSAPublicKey(fp, &c->rsa_key, NULL, NULL);
-      fclose(fp);
-      free(fname);
-    }
-
-  free(fname);
-
-  if(result)
-    return 0;
-  else
-    {
-      syslog(LOG_ERR, _("No public key for %s specified!"), c->name);
-      return -1;
-    }
-}
-
-int read_rsa_private_key(void)
-{
-  FILE *fp;
-  void *result;
-  char *fname, *key;
-cp
-  if(!myself->connection->rsa_key)
-    myself->connection->rsa_key = RSA_new();
+      for(snode = n->subnet_tree->head; snode; snode = snext)
+      {
+        snext = snode->next;
+        s = (subnet_t *)snode->data;
 
-  if(get_config_string(lookup_config(config_tree, "PrivateKey"), &key))
-    {
-      BN_hex2bn(&myself->connection->rsa_key->d, key);
-      BN_hex2bn(&myself->connection->rsa_key->e, "FFFF");
-    }
-  else if(get_config_string(lookup_config(config_tree, "PrivateKeyFile"), &fname))
-    {
-      if((fp = fopen(fname, "r")) == NULL)
-        {
-          syslog(LOG_ERR, _("Error reading RSA private key file `%s': %m"),
-                fname);
-          return -1;
-        }
-      result = PEM_read_RSAPrivateKey(fp, &myself->connection->rsa_key, NULL, NULL);
-      fclose(fp);
-      if(!result)
+        for(cnode = connection_tree->head; cnode; cnode = cnode->next)
         {
-          syslog(LOG_ERR, _("Reading RSA private key file `%s' failed: %m"),
-                fname);
-          return -1;
+          c = (connection_t *)cnode->data;
+          if(c->status.active)
+            send_del_subnet(c, s);
         }
-    }
-  else
-    {
-      syslog(LOG_ERR, _("No private key for tinc daemon specified!"));
-      return -1;
-    }
-cp
-  return 0;
-}
-
-/*
-  Configure node_t myself and set up the local sockets (listen only)
-*/
-int setup_myself(void)
-{
-  config_t *cfg;
-  subnet_t *subnet;
-  char *name, *mode;
-  int choice;
-cp
-  myself = new_node();
-  myself->connection = new_connection();
-  init_configuration(&myself->connection->config_tree);
-
-  asprintf(&myself->hostname, _("MYSELF"));
-  asprintf(&myself->connection->hostname, _("MYSELF"));
-
-  myself->connection->options = 0;
-  myself->connection->protocol_version = PROT_CURRENT;
-
-  if(!get_config_string(lookup_config(config_tree, "Name"), &name)) /* Not acceptable */
-    {
-      syslog(LOG_ERR, _("Name for tinc daemon required!"));
-      return -1;
-    }
-
-  if(check_id(name))
-    {
-      syslog(LOG_ERR, _("Invalid name for myself!"));
-      free(name);
-      return -1;
-    }
-
-  myself->name = name;
-  myself->connection->name = xstrdup(name);
-
-cp
-  if(read_rsa_private_key())
-    return -1;
-
-  if(read_connection_config(myself->connection))
-    {
-      syslog(LOG_ERR, _("Cannot open host configuration file for myself!"));
-      return -1;
-    }
 
-  if(read_rsa_public_key(myself->connection))
-    return -1;
-cp
-
-/*
-  if(RSA_check_key(rsa_key) != 1)
-    {
-      syslog(LOG_ERR, _("Invalid public/private keypair!"));
-      return -1;
-    }
-*/
-  if(!get_config_port(lookup_config(myself->connection->config_tree, "Port"), &myself->port))
-    myself->port = 655;
-
-  myself->connection->port = myself->port;
-
-/* Read in all the subnets specified in the host configuration file */
-
-  cfg = lookup_config(myself->connection->config_tree, "Subnet");
-
-  while(cfg)
-    {
-      if(!get_config_subnet(cfg, &subnet))
-        return -1;
-
-      subnet_add(myself, subnet);
-
-      cfg = lookup_config_next(myself->connection->config_tree, cfg);
-    }
-
-cp
-  /* Check some options */
-
-  if(get_config_bool(lookup_config(config_tree, "IndirectData"), &choice))
-    if(choice)
-      myself->options |= OPTION_INDIRECT;
-
-  if(get_config_bool(lookup_config(config_tree, "TCPOnly"), &choice))
-    if(choice)
-      myself->options |= OPTION_TCPONLY;
-
-  if(get_config_bool(lookup_config(myself->connection->config_tree, "IndirectData"), &choice))
-    if(choice)
-      myself->options |= OPTION_INDIRECT;
-
-  if(get_config_bool(lookup_config(myself->connection->config_tree, "TCPOnly"), &choice))
-    if(choice)
-      myself->options |= OPTION_TCPONLY;
+        subnet_del(n, s);
+      }
 
-  if(myself->options & OPTION_TCPONLY)
-    myself->options |= OPTION_INDIRECT;
+      for(enode = n->edge_tree->head; enode; enode = enext)
+      {
+        enext = enode->next;
+        e = (edge_t *)enode->data;
 
-  if(get_config_string(lookup_config(config_tree, "Mode"), &mode))
-    {
-      if(!strcasecmp(mode, "router"))
-        routing_mode = RMODE_ROUTER;
-      else if (!strcasecmp(mode, "switch"))
-        routing_mode = RMODE_SWITCH;
-      else if (!strcasecmp(mode, "hub"))
-        routing_mode = RMODE_HUB;
-      else
+        for(cnode = connection_tree->head; cnode; cnode = cnode->next)
         {
-          syslog(LOG_ERR, _("Invalid routing mode!"));
-          return -1;
+          c = (connection_t *)cnode->data;
+          if(c->status.active)
+            send_del_edge(c, e);
         }
-    }
-  else
-    routing_mode = RMODE_ROUTER;
 
-cp
-  /* Open sockets */
-  
-  if((tcp_socket = setup_listen_socket(myself->port)) < 0)
-    {
-      syslog(LOG_ERR, _("Unable to set up a listening TCP socket!"));
-      return -1;
-    }
+        edge_del(e);
+      }
 
-  if((udp_socket = setup_vpn_in_socket(myself->port)) < 0)
-    {
-      syslog(LOG_ERR, _("Unable to set up a listening UDP socket!"));
-      return -1;
+      node_del(n);
     }
+  }
 cp
-  /* Generate packet encryption key */
-
-  myself->cipher = EVP_bf_cbc();
-
-  myself->keylength = myself->cipher->key_len + myself->cipher->iv_len;
-
-  myself->key = (char *)xmalloc(myself->keylength);
-  RAND_pseudo_bytes(myself->key, myself->keylength);
-
-  if(!get_config_int(lookup_config(config_tree, "KeyExpire"), &keylifetime))
-    keylifetime = 3600;
-
-  keyexpires = time(NULL) + keylifetime;
-cp
-  /* Done */
-
-  myself->nexthop = myself;
-  myself->via = myself;
-  myself->status.active = 1;
-  node_add(myself);
-
-  syslog(LOG_NOTICE, _("Ready: listening on port %hd"), myself->port);
-cp
-  return 0;
 }
 
 /*
-  setup all initial network connections
+  Terminate a connection:
+  - Close the socket
+  - Remove associated edge and tell other connections about it if report = 1
+  - Check if we need to retry making an outgoing connection
+  - Deactivate the host
 */
-int setup_network_connections(void)
+void terminate_connection(connection_t *c, int report)
 {
+  avl_node_t *node;
+  connection_t *other;
 cp
-  init_connections();
-  init_subnets();
-  init_nodes();
-  init_vertices();
-
-  if(get_config_int(lookup_config(config_tree, "PingTimeout"), &timeout))
-    {
-      if(timeout < 1)
-        {
-          timeout = 86400;
-        }
-    }
-  else
-    timeout = 60;
-
-  if(setup_device() < 0)
-    return -1;
+  if(c->status.remove)
+    return;
 
-  /* Run tinc-up script to further initialize the tap interface */
-  execute_script("tinc-up");
+  if(debug_lvl >= DEBUG_CONNECTIONS)
+    syslog(LOG_NOTICE, _("Closing connection with %s (%s)"),
+           c->name, c->hostname);
 
-  if(setup_myself() < 0)
-    return -1;
+  c->status.remove = 1;
 
-  signal(SIGALRM, try_outgoing_connections);
-  alarm(5);
-cp
-  return 0;
-}
+  if(c->socket)
+    close(c->socket);
 
-/*
-  close all open network connections
-*/
-void close_network_connections(void)
-{
-  avl_node_t *node, *next;
-  connection_t *c;
-cp
-  for(node = connection_tree->head; node; node = next)
+  if(c->edge)
     {
-      next = node->next;
-      c = (connection_t *)node->data;
-      c->status.outgoing = 0;
-      terminate_connection(c, 0);
-    }
-
-//  terminate_connection(myself, 0);
-
-//  destroy_trees();
-
-  execute_script("tinc-down");
-
-  close_device();
-cp
-  return;
-}
-
-/*
-  handle an incoming tcp connect call and open
-  a connection to it.
-*/
-connection_t *create_new_connection(int sfd)
-{
-  connection_t *c;
-  struct sockaddr_in ci;
-  int len = sizeof(ci);
-cp
-  c = new_connection();
+      if(report)
+        {
+          for(node = connection_tree->head; node; node = node->next)
+            {
+              other = (connection_t *)node->data;
+              if(other->status.active && other != c)
+                send_del_edge(other, c->edge);
+            }
+        }
 
-  if(getpeername(sfd, (struct sockaddr *) &ci, (socklen_t *) &len) < 0)
-    {
-      syslog(LOG_ERR, _("System call `%s' failed: %m"),
-            "getpeername");
-      close(sfd);
-      return NULL;
+      edge_del(c->edge);
     }
 
-  c->address = ntohl(ci.sin_addr.s_addr);
-  c->hostname = hostlookup(ci.sin_addr.s_addr);
-  c->port = htons(ci.sin_port);                                /* This one will be overwritten later */
-  c->socket = sfd;
-  c->last_ping_time = time(NULL);
+  /* Run MST and SSSP algorithms */
 
-  if(debug_lvl >= DEBUG_CONNECTIONS)
-    syslog(LOG_NOTICE, _("Connection from %s port %d"),
-         c->hostname, htons(ci.sin_port));
+  graph();
 
-  c->allow_request = ID;
-cp
-  return c;
-}
+  /* Check if this was our outgoing connection */
 
-/*
-  put all file descriptors in an fd_set array
-*/
-void build_fdset(fd_set *fs)
-{
-  avl_node_t *node;
-  connection_t *c;
-cp
-  FD_ZERO(fs);
-
-  for(node = connection_tree->head; node; node = node->next)
-    {
-      c = (connection_t *)node->data;
-      FD_SET(c->socket, fs);
-    }
-
-  FD_SET(tcp_socket, fs);
-  FD_SET(udp_socket, fs);
-  FD_SET(device_fd, fs);
-cp
-}
-
-/*
-  receive incoming data from the listening
-  udp socket and write it to the ethertap
-  device after being decrypted
-*/
-void handle_incoming_vpn_data(void)
-{
-  vpn_packet_t pkt;
-  int x, l = sizeof(x);
-  struct sockaddr_in from;
-  socklen_t fromlen = sizeof(from);
-  node_t *n;
-cp
-  if(getsockopt(udp_socket, SOL_SOCKET, SO_ERROR, &x, &l) < 0)
-    {
-      syslog(LOG_ERR, _("This is a bug: %s:%d: %d:%m"),
-            __FILE__, __LINE__, udp_socket);
-      return;
-    }
-  if(x)
+  if(c->outgoing)
     {
-      syslog(LOG_ERR, _("Incoming data socket error: %s"), strerror(x));
-      return;
+      retry_outgoing(c->outgoing);
+      c->outgoing = NULL;
     }
 
-  if((pkt.len = recvfrom(udp_socket, (char *) pkt.salt, MTU, 0, (struct sockaddr *)&from, &fromlen)) <= 0)
-    {
-      syslog(LOG_ERR, _("Receiving packet failed: %m"));
-      return;
-    }
+  /* Deactivate */
 
-  n = lookup_node_udp(ntohl(from.sin_addr.s_addr), ntohs(from.sin_port));
-
-  if(!n)
-    {
-      syslog(LOG_WARNING, _("Received UDP packets on port %hd from unknown source %x:%hd"), myself->port, ntohl(from.sin_addr.s_addr), ntohs(from.sin_port));
-      return;
-    }
-/*
-  if(n->connection)
-    n->connection->last_ping_time = time(NULL);
-*/
-  receive_udppacket(n, &pkt);
+  c->status.active = 0;
+  if(c->node)
+    c->node->connection = NULL;
+  do_prune = 1;
 cp
 }
 
-/*
-  Terminate a connection:
-  - Close the sockets
-  - Remove associated hosts and subnets
-  - Deactivate the host
-  - Since it might still be referenced, put it on the prune list.
-  - If report == 1, then send DEL_HOST messages to the other tinc daemons.
-*/
-void terminate_connection(connection_t *c, int report)
-{
-  /* Needs a serious rewrite. */
-}
-
 /*
   Check if the other end is active.
   If we have sent packets, but didn't receive any,
@@ -966,17 +239,17 @@ cp
     {
       next = node->next;
       c = (connection_t *)node->data;
-      if(c->last_ping_time + timeout < now)
+      if(c->last_ping_time + pingtimeout < now)
         {
           if(c->status.active)
             {
               if(c->status.pinged)
                 {
                   if(debug_lvl >= DEBUG_PROTOCOL)
-                   syslog(LOG_INFO, _("%s (%s) didn't respond to PING"),
-                          c->name, c->hostname);
-                 c->status.timeout = 1;
-                 terminate_connection(c, 1);
+                    syslog(LOG_INFO, _("%s (%s) didn't respond to PING"),
+                           c->name, c->hostname);
+                  c->status.timeout = 1;
+                  terminate_connection(c, 1);
                 }
               else
                 {
@@ -996,126 +269,81 @@ cp
 }
 
 /*
-  accept a new tcp connect and create a
-  new connection
+  check all connections to see if anything
+  happened on their sockets
 */
-int handle_new_meta_connection()
+void check_network_activity(fd_set *f)
 {
-  connection_t *new;
-  struct sockaddr client;
-  int fd, len = sizeof(client);
+  connection_t *c;
+  avl_node_t *node;
+  int result, i;
+  int len = sizeof(result);
+  vpn_packet_t packet;
 cp
-  if((fd = accept(tcp_socket, &client, &len)) < 0)
+  if(FD_ISSET(device_fd, f))
     {
-      syslog(LOG_ERR, _("Accepting a new connection failed: %m"));
-      return -1;
+      if(!read_packet(&packet))
+        route_outgoing(&packet);
     }
 
-  if(!(new = create_new_connection(fd)))
+  for(i = 0; i < listen_sockets; i++)
     {
-      shutdown(fd, 2);
-      close(fd);
-      syslog(LOG_NOTICE, _("Closed attempted connection"));
-      return 0;
+      if(FD_ISSET(udp_socket[i], f))
+       handle_incoming_vpn_data(udp_socket[i]);
+      if(FD_ISSET(tcp_socket[i], f))
+       handle_new_meta_connection(tcp_socket[i]);
     }
 
-  connection_add(new);
-
-  send_id(new);
-cp
-  return 0;
-}
-
-void randomized_alarm(int seconds)
-{
-  unsigned char r;
-  RAND_pseudo_bytes(&r, 1);
-  alarm((seconds * (int)r) / 128 + 1);
-}
-
-/* This function is severely fucked up.
-   We want to redesign it so the following rules apply:
-   
-   - Try all ConnectTo's in a row:
-     - if a connect() fails, try next one immediately,
-     - if it works, wait 5 seconds or so.
-   - If none of them were succesful, increase delay and retry.
-   - If all were succesful, don't try anymore.
-*/
-
-RETSIGTYPE
-try_outgoing_connections(int a)
-{
-  static config_t *cfg = NULL;
-  static int retry = 0;
-  char *name;
-cp
-  if(!cfg)
-    cfg = lookup_config(config_tree, "ConnectTo");
-
-  if(!cfg)
-    return;
-
-  while(cfg)
+  for(node = connection_tree->head; node; node = node->next)
     {
-      get_config_string(cfg, &name);
-      cfg = lookup_config_next(config_tree, cfg);  /* Next time skip to next ConnectTo line */
-
-      if(!setup_outgoing_connection(name))   /* function returns 0 when there are no problems */
-        retry = 1;
-
-    }
+      c = (connection_t *)node->data;
 
-  get_config_int(lookup_config(config_tree, "MaxTimeout"), &maxtimeout);
+      if(c->status.remove)
+        return;
 
-  if(retry)
-    {
-      seconds_till_retry += 5;
-      if(seconds_till_retry > maxtimeout)    /* Don't wait more than MAXTIMEOUT seconds. */
-        seconds_till_retry = maxtimeout;
-
-      syslog(LOG_ERR, _("Failed to setup all outgoing connections, will retry in %d seconds"),
-        seconds_till_retry);
-  
-      /* Randomize timeout to avoid global synchronisation effects */
-      randomized_alarm(seconds_till_retry);
-    }
-  else
-    {
-      seconds_till_retry = 5;
+      if(FD_ISSET(c->socket, f))
+        {
+          if(c->status.connecting)
+            {
+              c->status.connecting = 0;
+              getsockopt(c->socket, SOL_SOCKET, SO_ERROR, &result, &len);
+              if(!result)
+                finish_connecting(c);
+              else
+                {
+                  if(debug_lvl >= DEBUG_CONNECTIONS)
+                    syslog(LOG_DEBUG, _("Error while connecting to %s (%s): %s"), c->name, c->hostname, strerror(result));
+                  close(c->socket);
+                  do_outgoing_connection(c);
+                  continue;
+                }
+            }
+          if(receive_meta(c) < 0)
+            {
+              terminate_connection(c, c->status.active);
+              return;
+            }
+        }
     }
 cp
 }
 
-/*
-  check all connections to see if anything
-  happened on their sockets
-*/
-void check_network_activity(fd_set *f)
+void prune_connections(void)
 {
   connection_t *c;
-  avl_node_t *node;
+  avl_node_t *node, *next;
 cp
-  if(FD_ISSET(udp_socket, f))
-    handle_incoming_vpn_data();
-
-  for(node = connection_tree->head; node; node = node->next)
+  for(node = connection_tree->head; node; node = next)
     {
+      next = node->next;
       c = (connection_t *)node->data;
 
       if(c->status.remove)
-       return;
-
-      if(FD_ISSET(c->socket, f))
-       if(receive_meta(c) < 0)
-         {
-           terminate_connection(c, c->status.active);
-           return;
-         }
+        connection_del(c);
     }
 
-  if(FD_ISSET(tcp_socket, f))
-    handle_new_meta_connection();
+  if(!connection_tree->head)
+    purge();
 cp
 }
 
@@ -1129,54 +357,50 @@ void main_loop(void)
   int r;
   time_t last_ping_check;
   int t;
-  vpn_packet_t packet;
+  event_t *event;
 cp
   last_ping_check = time(NULL);
 
+  srand(time(NULL));
+
   for(;;)
     {
-      tv.tv_sec = timeout;
+      tv.tv_sec = 1 + (rand() & 7); /* Approx. 5 seconds, randomized to prevent global synchronisation effects */
       tv.tv_usec = 0;
 
       build_fdset(&fset);
 
       if((r = select(FD_SETSIZE, &fset, NULL, NULL, &tv)) < 0)
         {
-         if(errno != EINTR) /* because of alarm */
+          if(errno != EINTR) /* because of a signal */
             {
-              syslog(LOG_ERR, _("Error while waiting for input: %m"));
+              syslog(LOG_ERR, _("Error while waiting for input: %s"), strerror(errno));
               return;
             }
         }
 
-      if(sighup)
-        {
-          syslog(LOG_INFO, _("Rereading configuration file and restarting in 5 seconds"));
-          sighup = 0;
-          close_network_connections();
-          exit_configuration(&config_tree);
-
-          if(read_server_config())
-            {
-              syslog(LOG_ERR, _("Unable to reread configuration file, exiting"));
-              exit(1);
-            }
-
-          sleep(5);
+      if(r > 0)
+        check_network_activity(&fset);
 
-          if(setup_network_connections())
-            return;
+      if(do_prune)
+        {
+          prune_connections();
+          do_prune = 0;
+        }
 
-          continue;
+     if(do_purge)
+        {
+          purge();
+          do_purge = 0;
         }
 
       t = time(NULL);
 
       /* Let's check if everybody is still alive */
 
-      if(last_ping_check + timeout < t)
-       {
-         check_dead_connections();
+      if(last_ping_check + pingtimeout < t)
+        {
+          check_dead_connections();
           last_ping_check = time(NULL);
 
           /* Should we regenerate our key? */
@@ -1190,20 +414,49 @@ cp
               send_key_changed(myself->connection, myself);
               keyexpires = time(NULL) + keylifetime;
             }
-       }
+        }
 
-      if(r > 0)
+
+      while((event = get_expired_event()))
         {
-          check_network_activity(&fset);
+          event->handler(event->data);
+          free(event);
+        }
 
-          /* local tap data */
-          if(FD_ISSET(device_fd, &fset))
+      if(sigalrm)
+        {
+          syslog(LOG_INFO, _("Flushing event queue"));
+
+          while(event_tree->head)
             {
-              if(read_packet(&packet))
-                return;
-              else
-                route_outgoing(&packet);
+              event = (event_t *)event_tree->head->data;
+              event->handler(event->data);
+              event_del(event);
+            }
+          sigalrm = 0;
+        }
+
+      if(sighup)
+        {
+          sighup = 0;
+          close_network_connections();
+          exit_configuration(&config_tree);
+
+          syslog(LOG_INFO, _("Rereading configuration file and restarting in 5 seconds"));
+          sleep(5);
+
+          init_configuration(&config_tree);
+
+          if(read_server_config())
+            {
+              syslog(LOG_ERR, _("Unable to reread configuration file, exiting"));
+              exit(1);
             }
+
+          if(setup_network_connections())
+            return;
+
+          continue;
         }
     }
 cp